Treadmill with vertically displaceable platform

ABSTRACT

A treadmill has a base with a vertically displaceable platform. A mechanism is provided that resists the downward movement of the platform in response to a load applied to the platform. The mechanism also rebounds the platform upwardly with a force applied to the platform in response to a decrease of a load on the platform. A support structure enables stable vertical positioning of the platform with respect to the base.

CROSS-REFERENCE TO RELATED APPLICATIONS AND PRIORITY CLAIM

This application is a divisional of co-pending U.S. patent applicationSer. No. 15/991,499, filed May 29, 2018, titled “Treadmill withVertically Displaceable Platform,” which claims priority to U.S.Provisional Patent App. No. 62/512,769, filed May 31, 2017, titled“Treadmill with Vertically Displaceable Platform” and also to U.S.Provisional Patent App. No. 62/512,770, filed May 31, 2017, titled“Treadmill Dynamic Belt Tensioning System.” These applications areassigned to the same entity as the present application, and are eachincorporated herein by reference in the entirety. This application isalso related by subject matter to U.S. patent Application Ser. No.15/991,891, filed May 29, 2018, titled “Treadmill with Dynamic BeltTensioning System,” which also claims priority to the two above-listedprovisional applications, and which is also assigned to the same entityas the present application, and which is also incorporated herein byreference in the entirety.

TECHNICAL FIELD

This disclosure describes a treadmill with a vertically displaceableuser engagement platform.

BACKGROUND

A treadmill has an endless belt powered by a drive roller. The belt isthe surface upon which a user engages in an activity. The endless beltresults in the user being able to engage in an activity in a relativelydefined space.

SUMMARY

This summary is intended to introduce a selection of concepts in asimplified form that are further described below in the detaileddescription section of this disclosure. This summary is not intended toidentify key or essential features of the claimed subject matter, and isalso not intended to be used as an aid in isolation to determine thescope of the claimed subject matter.

In brief, and at a high level, this disclosure describes, among otherthings, treadmills, including those having verticallydisplaceable/controllable platforms. In one aspect hereof, a treadmillincludes a mechanism coupled to the platform and to a base of thetreadmill to resist downward movement of the platform in response to aload applied to the platform and also to rebound the platform upwardwith a force applied to the platform in response to a decrease in loadapplied to the platform. In another aspect, a support structure iscoupled to the platform and to the mechanism to provide stable verticalpositioning of the platform with respect to the base. In other aspects,a displacement-based lighting system is integrated with the treadmill toprovide visual/color-based indicators for various functions and statesof the treadmill. In another aspect, a position-sensor-based speedcontrol system is integrated with the treadmill to assist in controllinga speed of the treadmill based on a position of a user/runner. In yetanother aspect, a method of operating a treadmill is provided.

In one aspect hereof, a vertical displacement apparatus for use in atreadmill is provided. The treadmill comprises a base and a trainingengagement platform supported above the base by a first supportstructure, the first support structure including a first scissor armconnected on a first end to the platform and connected on a second endto the base and a second scissor arm connected on a first end to thebase and connected on a second end to the platform. Further, anintermediate portion of the first scissor arm is pivotally attached toan intermediate portion of the second scissor arm so that pivoting ofthe first and second scissor arms with respect to one another results insupport of the platform at various vertical displacements.

In another aspect hereof, an adjustable treadmill is provided. Thetreadmill comprises a base, a platform movably coupled to the base, adrive roller rotatably coupled to the base, an endless belt movablycoupled to the drive roller and extending over a top surface of theplatform, a resistance/rebound mechanism coupled to the base and to theplatform and capable of providing displacement resistance in a firstdirection and rebound responsiveness in an opposite second direction,and a control system capable of applying input control signals to theresistance/rebound mechanism.

In another aspect hereof, an adjustable treadmill is provided. Thetreadmill comprises a base, a platform movably coupled to the base, adrive roller rotatably coupled to the base, an endless belt movablycoupled to the drive roller and extending over a top surface of theplatform, a linear actuator mounted to the base that has a piston thatis capable of extension and retraction, such that the linear path of thepiston is generally parallel to the platform, and a bell crank pivotallymounted to the base and having a first end coupled to the piston and asecond end coupled to the platform. The bell crank converts the linearpath of the piston approximately perpendicular to the platform.

In another aspect hereof, an exercise engagement platform for atreadmill is provided. The treadmill comprises a first layer of metal, asecond layer of carbon fiber, and a third layer of foam.

In another aspect, a method of operating a treadmill with a base and aplatform movably attached to the base is provided. The method comprisesresisting the downward movement of the platform in response to a controlinput indicating a load is applied to the platform and rebounding theplatform upwards with a force applied to the platform in response to acontrol input indicating a decrease of a load on the platform.

DESCRIPTION OF THE DRAWINGS

Aspects hereof are described in detail herein with reference to theattached drawing figures, in which like numerals refer to like elements,wherein:

FIG. 1 depicts a top perspective view of a treadmill with a verticallydisplaceable user platform, in accordance with an aspect hereof;

FIG. 2 depicts a side elevation view of the treadmill of FIG. 1, inaccordance with an aspect hereof;

FIG. 3 depicts a top perspective view of a vertical displacementmechanism with a user platform shown in dashed lines, in accordance withan aspect hereof;

FIG. 4 depicts a side elevation view of the vertical displacementmechanism of FIG. 3 with a user platform shown in dashed lines, inaccordance with an aspect hereof;

FIG. 5 depicts a side elevation view of a longitudinal pair of scissorarms of the displacement mechanism of FIG. 4, in accordance with anaspect hereof;

FIG. 6 depicts a top perspective view of the longitudinal pair ofscissor arms of FIG. 5, in accordance with an aspect hereof;

FIG. 7 depicts an end elevation view of the longitudinal pair of scissorarms of FIG. 5, in accordance with an aspect hereof;

FIG. 8 depicts an end elevation view of the vertical displacementmechanism of FIG. 3 with a user platform shown in dashed lines, inaccordance with an aspect hereof;

FIG. 9 depicts a top perspective view of a lateral pair of scissor armsof the displacement mechanism of FIG. 8, in accordance with an aspecthereof;

FIG. 10 depicts a side elevation view of the lateral pair of scissorarms of FIG. 9, in accordance with an aspect hereof;

FIG. 11 depicts an end elevation view of the lateral pair of scissorarms of FIG. 9, in accordance with an aspect hereof;

FIG. 12 depicts a top exploded perspective view of the verticallydisplaceable user platform, in accordance with an aspect hereof;

FIG. 13 depicts a bottom exploded perspective view similar to FIG. 12,in accordance with an aspect hereof;

FIG. 14 depicts a cross section view taken along lines 14-14 of FIG. 12,in accordance with an aspect hereof;

FIG. 15 depicts a top perspective view of a plurality ofresistance/rebound mechanisms, in accordance with an aspect hereof;

FIG. 16 depicts a top perspective view of the resistance/reboundmechanisms of FIG. 15 with a user platform shown in dashed lines, inaccordance with an aspect hereof;

FIG. 17 depicts a top plan view of the resistance/rebound mechanisms ofFIG. 15, in accordance with an aspect hereof;

FIG. 18 depicts a top perspective view of one of the resistance/reboundmechanisms of FIG. 15, in accordance with an aspect hereof;

FIG. 19 depicts a side elevation view of the resistance/reboundmechanism of FIG. 18 in a first position corresponding to the userplatform being at a first vertical height, in accordance with an aspecthereof;

FIG. 20 depicts a side elevation view of the resistance/reboundmechanism of FIG. 18 in a second position corresponding to the userplatform being at a second vertical height, in accordance with an aspecthereof;

FIG. 21 depicts a top perspective view of a displacement-based lightingsystem with a user platform shown in dashed lines, in accordance with anaspect hereof;

FIG. 22 depicts a partial end perspective view of the displacement-basedlighting system of FIG. 21, in accordance with an aspect hereof;

FIG. 23 depicts a top perspective view of a linear encoder used in thedisplacement based lighting system of FIG. 21, in accordance with anaspect hereof;

FIG. 24 depicts a top perspective view of the position-based speedcontrol system, in accordance with an aspect hereof; and

FIG. 25 depicts an exemplary method of operating a treadmill with a userplatform movably attached to a base, in accordance with an aspecthereof.

DETAILED DESCRIPTION

The subject matter of this disclosure is described herein to meetstatutory requirements. However, this description is not intended tolimit the scope hereof. Rather, the claimed subject matter may beembodied in other ways, to include different steps, combinations ofsteps, features, and/or combinations of features, similar to thosedescribed in this disclosure, and in conjunction with other present orfuture technologies. Moreover, although the terms “step” and/or “block”may be used herein to identify different elements of methods employed,the terms should not be interpreted as implying any particular orderamong or between various steps or blocks except when the order isexplicitly described and required.

Referring to FIG. 1, a treadmill 10 having an exemplary verticallydisplaceable platform 12 is depicted. The treadmill 10 has a base 14 forsupporting the treadmill 10 on a suitable support surface. The platform12 is supported above the base 14 and is vertically movable to a numberof different vertical locations in response to user interaction on anupper surface 16. More specifically, the platform 12 is supported abovethe base 14 to allow the platform 12 to move relative to the base 14 inan up and down manner. The purpose of the up and down movement of theplatform 12 is to accommodate downward force exerted by a user on theupper surface 16 when preforming, for instance, a running or walkingmotion. During a running motion, for example, the platform 12 may bedisplaced downwardly with a resistance force as a user's foot strikesthe platform 12. Still further, as the user's foot is removed during arunning motion, the platform may be moved upwardly with a rebound forcein preparation for the user's other foot striking the upper surface 16.An exemplary support structure for supporting the platform 12 forvertical movement above base 14 is a vertical motion control mechanism18, as will be more fully described below.

Referring to FIGS. 1-2, the treadmill 10 also has an endless belt 20that provides the moving surface for a user to engage during usage ofthe treadmill 10. More specifically, the belt 20 has a fixedcircumference and moves over the upper surface 16 of the platform 12.Thus, as a user, for instance, walks or runs, the belt 20 is movedbeneath the user's feet to allow walking or running at a singlelocation. In addition to moving over the upper surface 16, the belt 20also moves under a bottom plate 22 of the base 14. More specifically,referring to FIGS. 1-2, the bottom plate 22 is supported above a groundsurface by a plurality of generally trapezoidal legs 24 that are alsopart of the base 14. The legs 24 are positioned along opposite edges 26of the plate 22. Still further, the legs 24 along each edge 26 areconnected by a support rib 28 extending downwardly from a lower surface30 of the bottom plate 22. The plate 22 also includes an upper surface32. The provision of a support rib 28 along each side of the bottomplate 22 defines a cavity 34 through which the belt 20 passes adjacentthe lower surface 30 of the bottom plate 22. In this manner, the belt 20is able to run in a continuous loop along the upper surface 16 of theplatform 12 and along the lower surface 30 of the bottom plate 22 of thebase 14.

Referring to FIGS. 1-2, a belt drive mechanism 36 is depicted. The beltdrive mechanism 36 serves to provide the endless motion to the belt 20so that the user has a continuous running/walking surface as the usermoves across the upper surface 38 of the belt 20. The belt drivemechanism 36 is used to adjust the speed at which the user runs orwalks. Any suitable control system can be used to adjust the speed ofthe belt drive mechanism 36 and correspondingly the speed of the belt20.

The belt drive mechanism 36 includes a drive roller 40 rotatably mountedto the base 14 by a pair of mounting brackets 42 positioned on oppositesides of the base 14. Only one of the mounting brackets 42 is depictedin FIGS. 1 and 2. The mounting brackets 42 extend upwardly from theupper surface 32 of the plate 22 of the base 14 and each provide a pivotbearing 44 for receiving an axle 46 of the drive roller 40. Theprovision of the axle 46 rotatably mounted in the pivot bearings 44allows the rotating motion of the drive roller 40. The drive roller 40is coupled to any suitable power source to drive the rotating motion ofthe drive roller 40 and correspondingly the belt 20. The power source isnot depicted in the figures, but can include, for example, an electricmotor or a hydraulic motor drivably coupled to the drive roller 40 by,for instance, a belt or chain system. The power source can also bedirectly acting on the axle 46 to accomplish the rotating motion.

Referring to FIGS. 1-2, the treadmill 10 also includes a transitionframework 48 for ensuring smooth transition of the belt 20 between thebase 14 and the platform 12, especially as the platform 12 is displacedbetween a number of vertical locations with respect to the base 14during operation of the treadmill 10. The transition framework 48 alsoprovides a stable surface that the user can use to get onto and off ofthe platform 12.

Referring to FIGS. 1-2, a dynamic belt tensioning mechanism 50 isdepicted and is disposed adjacent a forward end 52 of the treadmill 10.The tensioning mechanism 50 provides substantially constant tension onthe belt 20 as the platform 12 moves up and down in relation to the base14. More specifically, the belt 20 has a fixed circumference. As theplatform 12 moves up and down, the spatial relationship between theplatform 12 and the base 14 is dynamically changing. Without the belttensioning mechanism 50, slack may exist in the belt 20 as the platform12 moves downwardly towards the base 14. This slack would result inpossible disengagement of the belt 20 from the drive roller 40. Stillfurther, the slack may result in an unstable running surface on theupper surface 38 of the belt 20. The belt tensioning mechanism 50provides a substantially constant tension in the belt 20 no matter therelative vertical position of the platform 12 above the base 14.

Referring to FIGS. 1-2, the platform 12 further includes an operatorsupport frame 54 that includes a pair of vertically extending pillars 56fixedly mounted to opposite sides of the base 14 adjacent the lower ends58 of the pillars 56. The operator support frame 54 further includes aconsole 60 mounted between and adjacent to the upper ends 62 of thepillars 56. A pair of bracing arms 64 extend rearwardly from oppositesides of the console 60 to provide lateral support and stability for auser as they engage with the platform 12. The console 60 can includevarious sensors (as will be more fully described below) and displays ifdesired to monitor or inform the user.

Vertical Motion Control Mechanism

Referring to FIGS. 3-11, the vertical control mechanism 18 is depicted.The vertical control mechanism 18 allows vertical motion of andminimizes roll and pitch of the platform 12. The control mechanism 18includes a parallel pair of longitudinal scissor frameworks 100positioned adjacent the opposite edges 26 of the bottom plate 22 of thebase 14 and also a lateral scissor framework 102 positioned between andperpendicular to the longitudinal frameworks 100 near the midpoint ofthe plate 22.

Referring to FIGS. 4-7, each longitudinal scissor framework 100 includesa first scissor arm 104 pivotally mounted to a second scissor arm 106 ata pivot/bearing arrangement 108. A first/upper end 110 of the firstscissor arm 104 is pivotally connected to the platform 12 via apivot/bearing mounting bracket 112 and a pivot/bearing 114. Asecond/lower end 116 of the first scissor arm 104 is slidably mounted tothe upper surface 32 of the bottom plate 22 via a slide arrangement 118.The slide arrangement 118 includes a male protrusion 120 fixedly mountedto the upper surface 32 and a female mounting bracket 122 pivotallymounted to the second/lower end 116 via a pivot/bearing 114. The femalebracket 122 is able to slide along the male protrusion 120 via a groove124 formed in the female bracket 122. The slide arrangement 118 can be aprofile rail linear bearing or any other suitable sliding/bearingmechanism.

A first/lower end 126 of the second scissor arm 106 is pivotallyconnected to the upper surface 32 of the plate 22 via a pivot/bearingmounting bracket 112 and a pivot/bearing 114. A second/upper end 128 ofthe second scissor arm 106 is slidably mounted to the platform 12 via aslide arrangement 118. The slide arrangement 118 includes a maleprotrusion 120 fixedly mounted to the platform 12 and a female mountingbracket 122 pivotally mounted to the second/upper end 128 via apivot/bearing 114.

Referring to FIGS. 8-11, the lateral scissor framework 102 includes afirst scissor arm 130 pivotally mounted to a second scissor arm 132 at apivot/bearing 108. A first/upper end 134 of the first scissor arm 130 ispivotally connected to the platform 12 via a pivot/bearing mountingbracket 112 and a pivot/bearing 114. A second/lower end 136 of the firstscissor arm 130 is slidably mounted to the upper surface 32 of thebottom plate 22 via a slide arrangement 118. The slide arrangement 118includes a male protrusion 120 fixedly mounted to the upper surface 32and a female mounting bracket 122 pivotally mounted to the second/lowerend 136 via a pivot/bearing 114. The female bracket 122 is able to slidealong the male protrusion 120 via a groove 124 formed in the femalebracket 122.

A first/lower end 138 of the second scissor arm 132 is pivotallyconnected to the upper surface 32 of the plate 22 via a pivot/bearingmounting bracket 112 and a pivot/bearing 114. A second/upper end 140 ofthe second scissor arm 132 is slidably mounted to the platform 12 via aslide arrangement 118. The slide arrangement 118 includes a maleprotrusion 120 fixedly mounted to the platform 12 and a female mountingbracket 122 pivotally mounted to the second/upper end 140 via apivot/bearing 114.

The provision of the parallel pair of longitudinal scissor frameworks100 and the lateral scissor framework 102 provides a stable support toallow the up and down vertical movement of the platform 12 relative tothe base 14. More specifically, the connection points of the frameworks100 and 102 are positioned generally at all four corners of the platform12 and also at the midpoint along the longitudinal sides of the platform12. In this manner, roll and pitch of the platform 12 may be minimized.The slide arrangements 118 allow the pivoting action of the scissor armsof the longitudinal scissor frameworks 100 and the lateral scissorframework 102. This pivoting action of the arms allows the stablevertical movement of the platform 12 relative to the base 14. Stillfurther, the friction and wear associated with the vertical movement ofthe platform 12 is limited due to the limited friction points of thepivot/bearings 108 and 114 and the slide arrangements 118. Wear,friction, and inertia may be reduced because of the limited ratio ofrotation of the pivot/bearings 108 and 114 and the limited lineardisplacement on the linear bearing/slide arrangements 118. Additionallydue to the ratios of the arms of the scissor frameworks 100 and 102,inertia may be reduced.

Stiff Lightweight Treadmill Platform

Referring to FIGS. 12-14, an exemplary stiff lightweight platform 12designed to reduce or limit inertial effects and to increase forcemeasurement is depicted. The platform 12 includes a platform base 200formed of a relatively stiff material that allows the securement of themounting brackets 112 and the sliding arrangements 118 of thelongitudinal scissor frameworks 100 and the lateral scissor frameworks102. The exemplary platform base 200 can be constructed of a metalmaterial, such as aluminum, and provides a first layer for the platform12. The platform 12 includes a thin phenolic sheet 202 received in ashallow cavity 204 that forms the upper surface 206 of the platform base200. The sheet 202 may be bonded or otherwise attached to the uppersurface 206 to provide a more limited coefficient of friction with thebelt 20. The platform base 200 includes a latticed lower surface 208including a plurality of ribs 210 extending downwardly and forming aplurality of cavities 212. The latticed lower surface 208 providesrigidity to the platform 12 and also provides attaching bosses 214 forsecurement of mounting brackets 112 and sliding arrangements 118 asdescribed herein. The bosses 214 also provide mounting surfaces for theresistance/rebound mechanisms, as will be more fully described below.

The platform 12 also includes an insert 216 constructed to fill thecavities 212 of the latticed lower surface 208 of the platform base 200.More specifically, an upper surface 218 of the insert 216 includes aplurality of grooves 220 for receiving the ribs 210 of the platform base200. The upper surface 218 also includes apertures/recesses 222 forreceiving the bosses 214 to facilitate mounting of the brackets 112 andthe sliding arrangements 118. Referring to FIG. 14, the insert 216 maybe made of a foam inner layer 224 with a top relatively thin layer ofcarbon fiber 226 and a bottom relatively thin layer of carbon fiber 228bonded thereto. The foam can be polyurethane foam or any other suitablefoam material. The carbon fiber/polyurethane sandwich construction ofthe insert 216 helps to increase the section height of the platform 12to increase stiffness with reduced mass. The design of the platform 12may therefore minimize or reduce the mass of the platform (and in turnreduce the inertia) while maintaining a natural frequency of over 200Hz. The 200 Hz natural frequency is chosen to reduce or minimize theeffect of platform deflection when performing force measurements on thetreadmill 10, thus resulting in a more accurate load measurement.

The platform 12 also includes a frame 230 secured to the platform base200 by any suitable structure such as, for example, bolts or rivets. Theframe 230 includes longitudinal side members 232 and lateral sidemembers 234 which surround the platform base 200. A pair of idlerrollers 236 are rotatably mounted between the longitudinal side members232 adjacent a respective lateral side member 234. The idler rollers 236enhance the movement of the belt 20 over the upper surface 16 of theplatform 12.

Resistance/Rebound Mechanism

Referring to FIGS. 15-20, a plurality of resistance/rebound mechanisms300 a/300 b are depicted for controlling the vertical displacement ofthe platform 12 in both the downwardly and upwardly directions. As bestshown in FIGS. 15-17, six resistance/rebound mechanisms 300 a/300 b aredepicted for controlling the motion of the platform 12. The term“resistance” or “resistance force” as used herein includes theapplication of an upward force upon the platform 12 as the platform 12is displaced downwardly during a foot strike such that the downwarddisplacement is impeded. In this manner, the amount of downwarddisplacement of the platform 12 that the user experiences during a footstrike can be selectively controlled. The term “rebound” or “reboundforce” as used herein includes the application of an upward force uponplatform 12 to move the platform 12 upwardly as the user begins toremove her/his foot in preparation for another stride. In this manner, aselectively controlled amount of upward force applied through platform12 can be transferred to and assist a user during foot removal. Eachresistance/rebound mechanism 300 a/300 b includes a linear actuator 302mounted to the upper surface 32 of the plate 22 by a vertical mountingbracket 304. The mounting bracket 304 engages a cylinder 306 of theactuator 302 and supports the actuator 302 in an orientation that isgenerally horizontal and parallel to the plate 22. Positioned withineach cylinder 306 is a movable piston 308. The piston 308 moves inrelationship to the cylinder 306 in a linear manner. Thus, the piston308 moves linearly in a direction that is generally parallel to theplate 22. Each actuator 302 is able to both power the extension and theretraction of its piston 308. It is the powering of the extension andretraction of the piston 308 that provides the resistance and reboundfunctions of the mechanisms 300 a/300 b. One suitable exemplary actuatoris a voice coil actuator. Voice coil actuators (VCAs) are direct drive,limited motion devices that utilize a permanent magnet field and coilwinding (conductor) to produce a force that is directly proportional tothe electrical current applied to the coil. These non-commutatedelectromagnet devices are used in linear and rotary motion applicationsthat require linear force or torque output, and high acceleration, orhigh frequency oscillation. VCAs allow for a millimeter by millimetercontrol of both the resistance to the downward movement of the platform12 and the rebounding upward movement of the platform 12 in the aspectsdescribed herein. For the current application, a VCA can provide acombined performance for response time, load capacity, parasiticdamping, resolution, availability, system cost, packaging, and controlscomplexity. The VCA may have in aspects hereof a response time in the 1millisecond or lower range, which is sufficient to provide adequateresponsiveness of the resistance/rebound force to the platform 12. TheVCA also has a low internal damping due to the air gap, thus making itmore nimble to control than other actuators, in certain circumstances.

Each actuator 302 also has a buffer spring 310 that is positioned aroundthe piston 308 and between the cylinder front end 312 and an annularflange 314 fixed to the piston 308. The spring 310 can further smooththe application of the resistance and rebound forces to the platform 12.The springs 310 also may help to reduce the level of actuator currentthat is required to hold the platform 12 in its neutral position. Inother words, the springs 310 serve to keep the platform 12 up when nopower is supplied to an actuator 302.

A first end 316 of the piston 308 is pivotally connected to a first end318 of an actuator linkage 320 by a pin/ball joint 322. A second end 323of the linkage 320 is pivotally connected to a first pivot connectionpoint 324 of a bell crank 326 by a pin/ball joint 322. As will befurther described below, each bell crank 326 serves to convert thehorizontal resistance/rebound force of its respective actuator 302 to agenerally vertical resistance/rebound force that is applied to theplatform 12.

Each bell crank 326 is pivotally mounted between a pair of verticalsupport frames 328 attached to and extending upwardly from the uppersurface 32 of the plate 22. A pivot axle 330 is used to mount the bellcranks 326 between the respective support frames 328 and allow clockwiseand counterclockwise rotation of the bell crank 326. Each bell crank 326has a second connection point 332 pivotally attached to a first end 334of a platform linkage 336 by a pin/ball joint 322. A second end 338 ofthe platform linkage 336 is pivotally connected to the platform 12 via apin/ball joint 322 and a mounting bracket 340. Each mounting bracket 340is attached to a boss 214 formed on the lower surface 208 of theplatform base 200. Each platform linkage 336 can have a load celltransducer 342 for measuring the force input to the platform 12, asshown most clearly in FIG. 18.

Referring to FIGS. 18-20 the translation of the horizontalresistance/rebound motion of the actuator 302 to a substantiallyvertical resistance/rebound motion is described. As a downward force isapplied to the platform 12 by for instance a foot strike of a runner,the platform 12 is vertically displaced downwardly in a stable manner bythe vertical motion control mechanism 18. Each resistance/reboundmechanism 300 a/300 b will resist the downward displacement of theplatform 12 to a certain degree, depending on the desiredperformance/measurement characteristics of the treadmill 10. Theresistance is applied to the platform 12 via the mounting brackets 340fixedly attached to the platform base 200 and pivotally attached to theplatform linkage 336. As the platform 12 moves downwardly, the bellcrank 326 is rotated in a counterclockwise direction about the pivotaxle 330. As depicted in FIG. 20, the counterclockwise motion of thebell crank 326 results in retraction of the piston 308 of the linearactuator 302. This retraction is controlled by the actuator 302 applyinga resistance force. In this manner, the amount of displacement of theplatform 12 can be controlled on, for instance, a millimeter bymillimeter basis. As is apparent, if it is desirable to apply a reboundforce to platform 12 such that an upward force is applied to a runnersfoot, the linear actuator 302 is energized to extend the piston 308 toapply the rebound force. The extension of piston 308 results inclockwise motion of the bell crank 326 and, thus, the application of avertically upward rebound force to the platform 12 via the linkage 336.The amount of rebound force can be applied in a tuned manner to enhancethe performance and measurement capabilities of the treadmill 10. Theload cell transducers 342 can be used to measure the force inputs on theplatform 12 applied by a user. The measurements from transducers 342 canbe used to adjust the resistance/rebound forces applied to the platform12 by the actuators 302.

Additionally, the bell cranks 326 amplify the parallel linear motion ofthe actuators 302 such that the vertical motion traveled is greater thanthe horizontal linear motion. Referring to FIG. 19, the distance D2between the second connection point 332 of the bell crank 326 and thepivot axle 330 is greater than the distance D1 between the firstconnection point 324 and the pivot axle 330. The relationship of D2being greater than D1 results in any movement of the piston 308 beingamplified such that the actual upward or downward vertical movement ofthe platform 12 is greater than that of the extension or retractiontravel of the piston 308.

Thus, not only do the resistance/rebound mechanisms 300 a/300 b allowfor the compact positioning of the linear actuators 302 by allowing themto be positioned generally horizontally with the force convertedvertically, but they also amplify the travel distance of the linearactuator 302 as it is applied to the platform 12.

Referring to FIG. 17, the six resistance/rebound mechanisms 300 a/300 bare positioned generally toward the interior of the plate 22. In thismanner, the longitudinal scissor frameworks 100 are positioned on eachside of the cluster of the resistance/rebound mechanisms 300 a/300 b.Still further, the lateral scissor framework 102 cuts through the centerof the cluster of resistance/rebound mechanisms 300 a/300 b. Each of thefour peripheral resistance/rebound mechanisms 300 a are connected to theplatform base 200 at center connection points 344 via a suitable boss214. Each of the two intermediate resistance/rebound mechanisms 300 bare connected to the platform base 200 at connection points 346 adjacentthe midpoints of the lateral edges of the platform 12. This spacedapplication of force to the platform 12 allows for smooth and evenapplication of resistance and rebound forces. Any suitable controlsystem 348 can be used to actuate the resistance/rebound mechanisms 300.For example, if VCAs are used as the resistance/rebound mechanisms 300a/300 b and the control system 348 is electrical in nature, eachresistance/rebound mechanism 300 a/300 b may then be electricallyconnected to the control system 348 via electrical connections 350. Thecontrol system 348 provides electrical signals/input to theresistance/rebound mechanisms 300 a/300 b so that downward displacementof the platform 12 is impeded/resisted by application of a force to theplatform 12 and upward displacement is enhanced/rebounded also byapplying a force to the platform 12. Measurement inputs from the loadcell transducers 342 can be supplied to the control system 348 and usedto determine the appropriate electrical/inputs to send to actuators 302.For instance, the control system 348 can be used to simulate a widevariety of running surfaces (e.g., sand, gravel, etc.) throughadjustment of the resistance and rebound forces applied by themechanisms 300 a/300 b to the platform 12.

Displacement-Based Lighting System

Referring to FIGS. 21-23, a displacement-based lighting system 400 isdepicted and is capable of visually indicating the vertical downwarddisplacement of the platform 12 from a normalized start position. Thelighting system 400 includes three linear encoders 402 a/402 bpositioned between and coupled to the platform 12 and the plate 22 ofthe base 14. Two of the linear encoders 402 a are mounted adjacent thefront end 404 of the plate 22 via mounting structures 406. The mountingstructures 406 are secured to the upper surface 32 of the plate 22. Aside surface 408 of the linear encoders 402 a is attached to arespective mounting structure 406. Each linear encoder 402 a/402 b has alinear displaceable measurement piston 410 that is movable within thehousing 412 of the encoder 402 a/402 b. As the piston 410 moves withinthe housing 412, an amount of displacement is sensed and an appropriatesignal is sent via an electrical line 414 connected to the housing 412.An upper end 416 of the piston 410 is attached to the platform 12 suchthat up and down movement of the platform 12 cause linear movement ofthe piston 410 within the housing 412. In this manner, the encoders 402a/402 b can sense the displacement of the platform 12 and send anappropriate signal. The lighting system 400 further includes a rearlinear encoder 402 b mounted to and adjacent a rear edge 418 of theplate 22. The encoder 402 b has a lower mounting shaft 420 secured tothe upper surface 32 of the plate 22 via a bracket arrangement (notshown). The upper end 416 of the encoder 402 b secures to the platform12 and the encoder 402 b operates in the same manner as the encoders 402a.

The lighting system 400 also includes horizontally extending elongatedlighting arrangements 422. The lighting arrangements 422 are mounted tothe upper surface 32 of the plate 22 by brackets 424 and are capable ofilluminating different colors corresponding to the displacement value ofthe platform 12. One suitable type of lighting arrangement 422 is astring LED (light emitting diode) which can illuminate for instance thecolors green, yellow, and/or red with various intensities thereof. Eachlighting arrangement 422 is electrically connected (either directly orindirectly) to the encoders 402 via electrical line 414.

The lighting system 400 is used on the treadmill 10 to inform theoperator on the level of peak displacement that is being seen by therunner for each stride. During operation of the treadmill 10, theencoders 402 are used to sense the displacement of the platform 12 andto send and appropriate signal to the lighting arrangements 422 toreflect a specific color that corresponds to the displacement. Forinstance, one suitable color indication scale is: green is 0-15 mm,yellow is 15-30 mm, and red is over 30 mm. Other scales may be utilizedfor particular lighting segmentations. Lighting arrangements 422 canalso be used to reflect additional treadmill information such as, forinstance, the state of the treadmill 10. When the treadmill 10 is readyfor use. the lighting arrangements 422 may turn dark green and whenthere is a fault with the treadmill 10, the lighting arrangement mayturn dark red.

Position-Sensor-Based Speed Control System

Referring to FIG. 24, a position-sensor-based speed control system 500is depicted and is capable of sensing the position of the runner/walkerand adjusting the speed of the treadmill 10 based upon the runner'sposition on the platform 12. The speed control system 500 includes asensor 502 positioned on a user-facing surface 504 of the console 60.The sensor 502 can send out a signal 506 that is capable of determiningthe position of a treadmill user along the longitudinal length of theplatform 12. The sensor 502 points towards the runner/user and candetermine the distance from the sensor 502 to the runner/user. Based onthe user's position, the belt 20 can be sped up or slowed down to keepthe user in the middle of the platform 12. One suitable type of sensor502 is an infrared sensor. The speed control system 500 can be used toactively control the speed of the belt 20 to slow the speed as therunner slows due to fatigue without manual speed adjustment.

Method of Operating a Treadmill

Referring to FIG. 25, a method 600 of operating a treadmill, such as thetreadmill 10 described herein, with a base, such as the base 14described herein, and a vertically displaceable platform, such as theplatform 12 described herein, is depicted. The method 600 includes thestep 602 of resisting the downward movement of the platform in responseto a control input indicating a load is applied to the platform. Theresistance applied to the platform may be controllable at everymillimeter of travel in the downward direction. The method 600 alsoincludes the step 604 of rebounding the platform upwardly with a forceapplied to the platform in response to a control signal indicating adecrease of a load on the platform. The rebound responsiveness of theplatform may be controllable at every millimeter of travel in the upwarddirection.

From the foregoing, it will be seen that this invention is one welladapted to attain all the ends and objects hereinabove set forthtogether with other advantages which are obvious and which are inherentto the structure.

It will be understood that certain features and sub-combinations are ofutility and may be employed without reference to other features andsub-combinations. This is contemplated by and is within the scope of theclaims.

While specific elements and steps are discussed in connection to oneanother, it is understood that any element and/or steps provided hereinare contemplated as being combinable with any other elements and/orsteps regardless of explicit provision of the same while still beingwithin the scope provided herein. Since many possible embodiments may bemade of the disclosure without departing from the scope thereof, it isto be understood that all matter herein set forth or shown in theaccompanying drawings is to be interpreted as illustrative and not in alimiting sense.

What is claimed is:
 1. A treadmill, comprising: a base; a platformmovably coupled to the base; a drive roller rotatably coupled to thebase; a belt extending across the drive roller and the platform; and alinear actuator coupled between the base and the platform, the linearactuator comprising a voice coil actuator.
 2. The treadmill of claim 1,wherein the linear actuator is coupled to a piston.
 3. The treadmill ofclaim 2, wherein the linear actuator powers both extension andretraction of the piston.
 4. The treadmill of claim 2, wherein thepiston is extendable and retractable along a direction approximatelyparallel to a length of the platform.
 5. The treadmill of claim 4,further comprising a bell crank pivotally coupled to the base at a pivotpoint, wherein the bell crank comprises: a first end coupled to thepiston, and a second end coupled to the platform, wherein the bell crankconverts linear movement of the piston into a force appliedapproximately perpendicular to the platform.
 6. The treadmill of claim5, wherein the first end of the bell crank is spaced a first distancefrom the pivot point and the second end of the bell crank is spaced asecond distance from the pivot point, and wherein the second distance isgreater than the first distance so that a linear movement of the pistonis amplified when applied to the platform.
 7. The treadmill of claim 1,further comprising a pair of idler rollers rotatably mounted on thetreadmill.
 8. The treadmill of claim 1, wherein the linear actuator iscoupled to a load cell transducer.
 9. The treadmill of claim 1, whereinthe linear actuator comprises one of a plurality of linear actuatorseach coupled to a respective piston.
 10. The treadmill of claim 9,wherein the plurality of linear actuators form part of aresistance/rebound mechanism coupled to the base and to the platform,the resistance/rebound mechanism capable of providing selectivelycontrolled displacement resistance in a first direction and selectivelycontrolled rebound responsiveness in an opposite second direction.
 11. Aresistance/rebound mechanism for a treadmill, comprising: a linearactuator comprising a voice coil actuator; a transducer; and a bellcrank, wherein the linear actuator is coupled to the bell crank, andwherein extension or retraction of the linear actuator along a firstdirection translates into movement of the bell crank in a seconddirection that is approximately perpendicular to the first direction.12. The resistance/rebound mechanism of claim 11, wherein the bell crankcomprises a pivot point and a linkage.
 13. The resistance/reboundmechanism of claim 12, wherein the linkage comprises a first end and asecond end, wherein the first end is coupled to the bell crank at apivot connection, and wherein the second end is coupled to a mountingbracket.
 14. The resistance/rebound mechanism of claim 11, wherein thebell crank comprises one of a plurality of bell cranks.
 15. Theresistance/rebound mechanism of claim 11, wherein the resistance/reboundmechanism is capable of providing selectively controlled displacementresistance in a first direction and selectively controlled reboundresponsiveness in an opposite second direction.
 16. Theresistance/rebound mechanism of claim 11, further comprising a bufferspring coupled to the linear actuator.
 17. The resistance/reboundmechanism of claim 11, wherein the linear actuator is coupled to thebell crank at a pivot joint or a ball joint.
 18. A system for atreadmill, comprising: a plurality of resistance/rebound mechanisms eachcomprising: a linear actuator that comprises a voice coil actuator; atransducer, and a bell crank; wherein extension or retraction of thelinear actuator along a first direction translates into movement of thebell crank in a second direction that is approximately perpendicular tothe first direction.
 19. The system of claim 18, wherein the linearactuator is coupled to a piston, and wherein the linear actuator powersboth extension and retraction of the piston.
 20. The system of claim 18,wherein the plurality of resistance/rebound mechanisms comprise at leastfour resistance/rebound mechanisms positioned on a surface of thetreadmill.